Powered wood splitters are a boon to both professionals and weekend wood gatherers. Powered splitters greatly reduce the amount of time and effort required to split large wood blocks into more manageable size split pieces. Even so, conventional powered splitters are not without certain problems that detract from full efficiency and utility.
A first problem associated with splitters is the effective stroke length of the splitting blade. The stroke length for a splitter blade must be greater than the longest wood block to be split; splitters are therefore made with a relatively long stroke capacity for long blocks. The problem comes in the time required to complete the stroke when shorter blocks are to be split. Valuable time is wasted as the blade is moved from its beginning position into contact with a short block. Similarly, time is wasted when the blade is retracted to its beginning position after splitting the wood.
Stroke limiting apparatus have been developed as a solution to the above problem. For example, a wood splitter developed by Piqua Engineering, Inc. of Piqua, Iowa includes a ram return stop that is selectively adjustable along the frame of the splitting device for limiting the retracted position of a one-way ram cylinder. The return stop bar may be adjustably positioned in the path of the retracting ram to stop the ram at a desired position, thereby effectively adjusting the length of stroke. The cylinder involved is a "single acting" cylinder in which the return stroke of the ram is effected by a spring and cable mechanism. The ram is not hydraulically powered to return to its starting position but is instead returned by spring force. The stop is effective in this construction to prevent retraction of the ram simply by overcoming the relatively light spring tension used to pull the ram back to its starting position.
U.S. Pat. No. 2,851,072 to Gergets et al. discloses a wood splitting machine having a valve actuator mechanism that will effectively change the starting position of a movable platform. Here, a double acting hydraulic cylinder is provided and an arm is mounted to a movable platform connected to the cylinder for selectively contacting a valve actuator. The arm is positioned to actuate the valve at different retracted positions for the platform, thereby effectively adjusting the stroke length. This device effectively controls the positioning for the platform in conjunction with a double acting hydraulic cylinder. However, it requires very specific placement of the actuator valve in relation to the trip mechanism on the platform. Furthermore, adjustment is capable only within a range dictated by the swing path of the pivoted actuator bar.
U.S. Pat. No. 3,779,295 to Balsbaugh also discloses a stroke controlling arrangement by which a control rod is connected to a manual stroke control lever. The lever is connected to an actuator valve for selectively directing fluid to a double acting hydraulic cylinder. Collars on the control rod at opposite ends of a predetermined stroke length are engaged by a slider on the splitting blade carriage.
Another problem with powered wood splitters is that few provide mechanism by which wood can be stripped from a jammed position on the splitting blade. In the Balsbaugh patent a pivoted rod can be swung into position to abut a wood block jammed on the splitting wedge as the wedge reaches its fully retracted position. A stripping mechanism is disclosed in my prior U.S. Pat. No. 4,700,759 that functions to separate wood from the splitting head as the splitting head reaches its fully retracted position. This device includes the additional advantage of protecting the user's fingers by enclosing the blade within the stripping mechanism as it is lowered to the surface of the wood. However, the stripping function occurs only at the full retracted position of the blade.
Other stripping arrangements have been available in the past. For example, I have produced an earlier splitter form that includes a fixed stripping device that is affixed to the splitter frame and is positioned along the frame to strip wood from the splitting blade as the blade reaches its fully retracted position.
Of the above stripping mechanisms, none enable stripping of wood at any selected position along the length of the splitter frame. All require nearly full retraction of the splitter blade or wood support to complete the stripping function.
It therefore has remained a problem to obtain efficiency in wood splitters by adjusting the stroke length to accommodate wood of different length dimensions and for stripping wood from a blade that is selectively positioned for shorter stroke length on the frame.